001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2007, by Object Refinery Limited and Contributors.
006 *
007 * Project Info:  http://www.jfree.org/jfreechart/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it 
010 * under the terms of the GNU Lesser General Public License as published by 
011 * the Free Software Foundation; either version 2.1 of the License, or 
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but 
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
022 * USA.  
023 *
024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
025 * in the United States and other countries.]
026 *
027 * -----------------
028 * ChartDeleter.java
029 * -----------------
030  * (C) Copyright 2002-2007, by Richard Atkinson and Contributors.
031 *
032 * Original Author:  Richard Atkinson;
033 * Contributor(s):   -;
034 *
035 * Changes
036 * -------
037 * 19-Aug-2002 : Version 1;
038 * 17-Oct-2002 : Fixed errors reported by Checkstyle (DG);
039 * ------------- JFREECHART 1.0.x ---------------------------------------------
040 * 02-Feb-2007 : Removed author tags all over JFreeChart sources (DG);
041 *
042 */
043package org.jfree.chart.servlet;
044
045import java.io.File;
046import java.io.Serializable;
047import java.util.Iterator;
048import java.util.List;
049
050import javax.servlet.http.HttpSessionBindingEvent;
051import javax.servlet.http.HttpSessionBindingListener;
052
053/**
054 * Used for deleting charts from the temporary directory when the users session
055 * expires.
056 */
057public class ChartDeleter implements HttpSessionBindingListener, Serializable {
058
059    /** The chart names. */
060    private List chartNames = new java.util.ArrayList();
061
062    /**
063     * Blank constructor.
064     */
065    public ChartDeleter() {
066        super();
067    }
068
069    /**
070     * Add a chart to be deleted when the session expires
071     *
072     * @param filename  the name of the chart in the temporary directory to be 
073     *                  deleted.
074     */
075    public void addChart(String filename) {
076        this.chartNames.add(filename);
077    }
078
079    /**
080     * Checks to see if a chart is in the list of charts to be deleted
081     *
082     * @param filename  the name of the chart in the temporary directory.
083     *
084     * @return A boolean value indicating whether the chart is present in the 
085     *         list.
086     */
087    public boolean isChartAvailable(String filename) {
088        return (this.chartNames.contains(filename));
089    }
090
091    /**
092     * Binding this object to the session has no additional effects.
093     *
094     * @param event  the session bind event.
095     */
096    public void valueBound(HttpSessionBindingEvent event) {
097        return;
098    }
099
100    /**
101     * When this object is unbound from the session (including upon session
102     * expiry) the files that have been added to the ArrayList are iterated
103     * and deleted.
104     *
105     * @param event  the session unbind event.
106     */
107    public void valueUnbound(HttpSessionBindingEvent event) {
108
109        Iterator iter = this.chartNames.listIterator();
110        while (iter.hasNext()) {
111            String filename = (String) iter.next();
112            File file = new File(
113                System.getProperty("java.io.tmpdir"), filename
114            );
115            if (file.exists()) {
116                file.delete();
117            }
118        }
119        return;
120
121    }
122
123}